Course overview/Governance as agent context4 of 5
Capstone: defend the answer
Capstone: defend the answer
Build a churn-risk model, verify its headline three independent ways, and defend it under challenge.
The request is not yet a model
"Which customers are at risk of churning, and what revenue is at risk?" does not define at risk. Choose a threshold and reference date, write them down, implement them exactly, and make the limitations visible. The goal is a defensible answer, not a single hidden reference number.
Build five deliverables: a churn-risk contract, layered assets, column descriptions and metric metadata, three independent verifications, and docs/defence.md. The defence must answer what one row means, why this churn definition, what is excluded, and how confident you are. It must also state a truthful currency basis: this dataset contains five currencies, so a mixed-currency sum is not USD unless you convert it through the date-and-currency FX join.
Your task
Build the churn-risk model and complete all five deliverables. Then ask your agent to make the five strongest skeptical CFO objections, classify each as a real or presentational problem, and show the query behind every real one. Revise the work before asking for review.
Rubric
| Area | Points | Evidence |
|---|---|---|
| Contract quality | 2 | Six fields and a threshold with reference date |
| Layering | 2 | Staging, core, mart, and no raw-table mart dependency |
| Join and grain safety | 1 | Correct duplicate treatment and no customer fan-out |
| Governance | 2 | Mart descriptions plus metric definition and limitation |
| Verification | 2 | Three genuinely independent checks of the headline |
| Defence | 1 | Four answers, objections anticipated, truthful currency basis |
Optional extensions
- Ask a second model to attack the same defence and compare objections.
- Add a Bruin quality check for the defect you consider most likely to return.
- Implement a second churn definition in a separately named mart and explain how the population changes.
Answer key
Use course/answer-key.md only after your written defence is complete and you have requested review. The key grades evidence and objections; it does not make a different, well-specified churn definition invalid.
Check your understanding
- What makes three verifications independent rather than three copies of one?
- Your churn definition is "customers who have stopped buying". Why will that fail the contract?
- The agent raises an objection you had already thought of and rejected. Is that a failure of the defence?
Do it with your agent
Say next lesson, complete the written deliverables and adversarial pass, then say review my work. The review should inspect files and evidence before it opens the instructor-only answer key.